According to the World Health Organization, chikungunya is a mosquito-borne viral disease first described during an outbreak in southern Tanzania in 1952. It is an alphavirus of the family Togaviridae. The name ‘chikungunya’ derives from word in the Kimakonde language, meaning “to become contorted” and describes the stooped appearance of sufferers with joint pain.

Chikungunya is characterized by an abrupt onset of fever frequently accompanied by joint pain. Other common signs and symptoms include muscle pain, headache, nausea, fatigue and rash. The joint pain is often very debilitating, but usually lasts for a a few days or may be prolonged to weeks.

Most patients recover fully, but in some cases joint pain may persist for several months, or even years. Occasional cases of eye, neurological and heart complications have been reported, as well as gastrointestinal complaints. Serious complications are not common, but in older people, the disease can contribute to the cause of death.

The virus is transmitted from human to human by the bites of infected female mosquitoes. Most commonly, the mosquitoes involved are Aedes aegypti and Aedes albopictus, two species which can also transmit other mosquito-borne viruses, including dengue.

There is no specific antiviral drug treatment for chikungunya. Treatment is directed primarily at relieving the symptoms, including the joint pain. There is no commercial chikungunya vaccine.